Call mechanism for automatic telephone dialers



CALL. MECHANISM FbR AUTOMATIC TELEPHONE DIALERS Fil id D". 2, 1955 2}Sheets-Sheet 1 v '24 L j VI v y la L l7 l INVENTO THOMAS W. MAC KE E ATr (DRIVE 1 April 1, 1958 T. w. MacKENZIE 2,829,206

CALL MECHANISM FOR AUTOMATIC TELEPHONE 'DIALERS Filed Dec. 2, 1955 1 v r2 Sheets-Sheet 2 \j flan A TTOR/V5 k United States Patent CALL MECHANISMFOR AUTOMATIC TELEPHONE DIALERS Thomas W. MacKenzie, Cranford, N. J.

Application December 2, 1955, Serial No. 550,629

14 Claims. (Cl. 179-90) This invention relates to what are known asautomatic telephone dialers, where one of a number of keys are manuallyoperated to automatically call a telephone number, thereby dispensingwith the need of dialing the number as with the conventional dialtelephones.

More particularly, the invention deals with the call actuating mechanismof dialers of this type and kind employing a simple and economical typeof key construction and simple switch and switch operating means forpulsing the number through the control means of the key.

Still more particularly, the invention deals with a mechanism of thecharacter described, wherein a standard key blank can be employed andthe same simply and easily fashioned in producing thereon any desirednumber to be called in the use of the key in the automatic dialer.

The novel features of the invention will be best understood from thefollowing description, when taken together with the accompanyingdrawing, in which certain embodiments of the invention are disclosedand, in which, the separate parts are designated by suitable referencecharacters in each of the views and, in which:

Fig. 1 is a diagrammatic face view of the switch mechanism of a dialermade according to my invention, Showing the parts in normal inoperativeposition.

Fig. 2 is a partial detail section, substantially on the line 2--2 ofFig. 1.

Fig. 3 is a diagrammatic side view of a key in the normal inoperativeposition with associated operating mechanism illustrated in section andillustrating a top fingerpiece portion of the key in section.

Fig. 4 is a view, generally similar to Fig. 3, omitting parts of theconstruction and showing the key in the fully depressed position.

Fig. 5. is a view, similar to Fig. 4, showing the key in the callpulsing position; and

Fig. 6 is a diagrammatic view of part of the wiring diagram illustratingone of the key circuits in operative pulsing position.

My present invention deals with automatic telephone dialers, generallyof the type and kind disclosed in my prior Patent Number 2,407,889,granted September 17, 1946 and deals primarily with the call mechanismof dialers of this type and kind, that is to say, the manually actuatedkey and the switches controlling the circuits of the two banks of keyswhich are usually employed in dialers of the kind under consideration. I

In Fig. 1 of the drawing, I have diagrammatically shown the switch endportion of a dialer employing two left and right side spring tensionedgear shafts 10 and 11 suitably supported upon the end wall 12 of thedialer mechanism as a whole. The shafts 10 and 11 protrude beyond thewall 12 and have adjustably fixed thereto switch actuating elements 13and 14 composed of insulating material. The elements have projectingstepped lugs 15 and 16', one of which is clearly noted in Fig. 2 of thedrawing, to operatively engage contacts 17 and 18 and 17'', 18',respectively, to normally break the circuit between these contacts, thusrendering the dialer inoperative. However, in the rotation of either oneof the shafts 10 and 11, as later described, the element 13 or 14 willbe moved into inoperative position to close the circuit through theswitches. In Fig. 1 of the drawing, the element 13 is indicated ininoperative position in dotted lines, thus completing the circuitthrough the contacts 17 and 18 and this same dotted position isdiagrammatically illustrated in the wiring diagram of Fig. 6, thecontacts 17 and 18 being identified in this diagram.

Mounted on shafts 19 and 20 outwardly of the shafts 10 and 11 arepulsing pawls 21 and 22, respectively, which operate upon switchcontacts 23 and 24 in the pulsing operation of the circuit, in otherwords, in opening and closing the circuit between the contacts 23, 24and associate contacts 23', 24'. These contacts are alsodiagrammatically illustrated in the wiring diagram of Fig. 6 and it willappear that the contacts are normally closed and, with the left side ofthe circuit in operation, the contacts 23, 23 are shown open todiagrammatically illustrate the pulsing operation of the circuit.

The shafts 19 and 20, within the casing of the dialer, are of anirregular cross-sectional form, one of these shafts, the shaft 19, beingshown in Fig. 3 of the drawing. One side of the shaft has right anglesurfaces, as at 25; whereas, the other side has similar surfaces 26,cutaway, as seen at 27, and fashioned to form a pulsing flange 28, thelower surface 29 of which is preferably radial with respect to the endsof the shaft. As both shafts 19 and 20 are of the same construction,only one shaft is shown in detail and it will be understood that theshaft 20 is of the same structure. With this thought in mind, again onlyone key 3!} is illustrated,

' that is to say, one key in the row of keys that will be disposed inthe left hand side of the dialer. The righthand rows of keys are notshown, but these would be arranged adjacent the shaft 20, as will beapparent.

From a consideration of Fig. 3 of the drawing, it will appear that onlyone of the gear shafts are shown, namely the shaft 10, but here again,the shaft 11 will be of the same construction. One side of the key 30has a long rack 31 operatively engaging the teeth of the elongated gearportion it) of the shaft 10. The same side edge of the key, at its upperportion, has a conical type of recess 32 for receiving a yieldable lockpin 33 for normally supporting the key in raised inoperative position.When the key is depressed, this pin 33 is moved outwardly, as noted inFigs. 4 and 5, and when one key is depressed, other keys are lockedagainst movement. However, as this control forms no part of the presentinvention and is disclosed in the prior patent, no further detailedreference thereto will be made.

The other side edge of the key 30 has, at its lower portion, a recess 34and said side edge adjacent the recess 32 has a recess 35. Between therecesses 34 and 35, the last named side edge has a pulsing section 36which, in producing the keys, is cut with a predetermined number ofcontinuous teeth, part of these teeth being shown at 37 in Fig. 5. Thus,in producing a key for calling a predetermined telephone number, partsof the teeth of the section 36 are removed, as indicated at 38, therebyproducing spaced number pulsing units 39, and, in Fig. 5 of the drawingin illustrating one type of key, the cutouts, at 38, are such as toproduce a pulsing call number MU (Murray Hill) 6-8869. In other words,the number of teeth remaining in each unit 39 will actuate the pawl 21so as to transmit through the switch 23, first siX impulses, then eight,then six, then eight, then eight, then ten and then ten.

Normally, the element 28 is disposed in the recess 34 and, as the key 30is moved downwardly in the operation of placing a call, the element 28is moved downwardly, which raises the pawl 21. Upon completing thedownward movement of the key, the element 28 moves into the recess 35,as noted in Fig. 4 of the drawing, after which, the spring tensionedgear 10' operates to return the key to normal position, that is to say,to move the same upwardly; whereupon, the teeth of the various pulsatingunits 39 intermittently actuate the element 28, thereby actuating thepawl 21 to break the circuit between contacts 23, 23' in pulsing thecall.

The foregoing description is all centered around the single key and themechanism associated therewith. Considering Fig. 1 of the drawing, itwill appear that springs 40, 41 are coupled with the pawls 21 and to acommon post 42 on the wall 12, the springs operating to automaticallyremove the pawls from the contacts 23, 24 after said contacts have beenactuated by the pawls through the medium of hte elements 28.

The call operation, that is to say, the pulsing operation, is very quickand much faster than normal manual operation of the conventional dialerof a telephone. It will be understood that the key 30 must be fullydepressed before a call can be pulsed, as the element 28, in engagingthe teeth 37, would normally lock the key against upward movement. Thiswill be apparent from the position that the element 28 would assume whenthe key 30 is moved downwardly. In other words, the element 28 would bedirected downwardly rather than upwardly, as noted in Fig. of thedrawing.

The upper end portion of the key 30 has notches or recesses 43 onopposed edges thereof, with which a fingerpiece casing 44 is suitablycoupled, the key being held against displacement from the casing 44 by alock element 45. At the upper part of the casing is a characterizedplate 46 hearing the name of an individual, firm or station to becalled.

At this time, it is pointed out that dialers of the character describedwill have keys suitable for calling numbers which are called frequentlyand the characterized strip or plate 46 can have thereon any marking toidentify the individual or telephone number to be called. In the use ofthe dialer, all that is necessary is to remove the receiver of atelephone in the usual manner and simply depress the key of the numberwhich is desired; thereupon, the number is automatically called throughthe pulsing operation transmitted to either of the switches 23, 23 or24, 24'. Upon completing the call, the key 30 returns to the normalinoperative position shown in Fig. 3 of the drawing.

Fig. 4 shows the fully depressed position of the key, preparatory toperforming the pulsing operations. Fig. 5 shows the key in the operationof pulsing a call. However, no specific showing is made of the positionof the shaft 19 and the element 28 thereon in moving the key from theinoperative position of Fig. 3 to the lowered position of Fig. 4.

No showing of the circuit wires coupled with the various switchesdiagrammatically shown in Fig. 1 of the drawing is made, as this will beclear from the diagrammatic wiring diagram of Fig. 6 of the drawing.Aspreviously stated, normally the circuit is closed through the switches23, 23; 24, 24 and the circuit through the switches 17, 18; 17', 18 isnormally opened and held so by the elements 13 and 14. However, when akey in one side of the dialer such, for example, as the lefthand side isoperated, then the circuit is closed through switches 17 and 18 andthe'switches 23, 23 are in position for pulsing the call. In the samemanner, if a key of the righthand bank of keys is actuated, then thecircuit through switches 17 and 18 will remain open, circuit through thecontacts 23, 23' will be closed, the circuits through contacts 17', 18'will be completed and contacts 24, 24 will be in position for pulsing acall.

From a standpoint of production, it will be understood that a single keyblank is produced, this blank being fashioned to dial any telephonenumber by simply removing portions of the teeth of the section 36, asfor example, at 38 in Fig. 5 of the drawing, to specificallycharacterize the call units 39. The length of the section 36 will besufficient to dial any telephone number.

In some specific instances, shorter or longer sections 36 can beemployed in the key blanks. However, the key illustrated is designed forthe more conventional uses.

It will be understood that, when one of the keys is actuated, and thepulsing bar or its element 28 is in the upwardly tilted position, asnoted in Fig. 5 of the drawing, no other key engaging 28 can bedepressed, it being understood in this connection, that the element 28of the shaft or bar 19 extends the full length of the shaft tooperatively engage all keys in a single bank of keys.

It will be understood that the pawls 21 and 22, which are adjustablyfixed upon the ends of the shafts 19 and 20, be composed of insulatingmaterial, such as fibre, as will also the actuating elements 13 and 14.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In telephone dialers of the class described, a call actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an opposed tooth-like edge having pulsing sections,a pair of spaced shafts having longitudinal gear portions, said keysbeing spaced longitudinally of said gear portions with the gear racks ofsaid teeth in position to operatively engage said gear portions, anotherpair of shafts spaced from the first shafts and having longitudinallyextending pulsing elements adapted to operatively engage said pulsingsections, said first shafts being spring tensioned and having switchactuating members of insulating material on one end thereof, two pairsof contacts operated by said last named members and normally supportingthe contacts in open circuit position, the corresponding end of thesecond named shafts having insulated pulsing pawls mounted thereon, apair of pulsing contacts adjacent each pawl, and one of the contacts ofeach pair being actuated by the adjacent pawl in intermittently breakingcircuit through the last named contacts in pulsing a pre' determinedcall number by movement of one of the pulsing sections of a key over thepulsing element of the shaft to which said pawlis fixed.

2. In telephone dialers of the class described, a call actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an opposed tooth-like edge having pulsing sections,a pair of spaced shafts having longitudinal gear portions, said keysbeing spaced longitudinally of said gear portions with the gear racks ofsaid teeth in position to operatively engage said gear portions, anotherpair of shafts spaced from the first shafts and having longitudinallyextending pulsing elements adapted to operatively engage said pulsingsections, said first shafts being spring tensioned and having switchactuating members of insulating material on one end thereof, two pairsof contacts operated by said last named members and normally supportingthe contacts in open circuit position, the corresponding end of thesecond named shafts having insulated pulsing pawls mounted thereon, apair of pulsing contacts adjacent each pawl, one of the contacts of eachpair being actuated by the adjacent pawl in intermittently breakingcircuit through the last named contacts in pulsing a predetermined callnumber by movement of one of the pulsing sections of a key over thepulsing element of the shaft to which said pawl is fixed, and thecircuit through one pair of the first named contacts being closed byoperation of the switch actuating member on one of the first namedshafts in the depression of a key in setting the mechanism to dialingoperation.

3. In telephone dialers of the class described, a call actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an opposed tooth-like edge having pulsing sections,a pair of spaced shafts having longitudinal gear portions, said keysbeing spaced longitudinally of said gear portions with the gear racks ofsaid teeth in position to operatively engage said gear portions, anotherpair of shafts spaced from the first shafts and havinglongitudinallyextending pulsing elements adapted to operatively engage said pulsingsections, said first shafts being spring tensioned and having switchactuating members of insulating material on one end thereof,two pairs ofcontacts operated by said last named members and normally supporting thecontacts in open circuit position, the corresponding end of the secondnamed shafts having insulated pulsing pawls mounted thereon, a pair ofpulsing contacts adjacent each pawl, one of the contacts of each pairbeing actuated by the adjacent pawl in intermittently breaking circuitthrough the last named contacts in pulsing a predetermined call numberby movement of one of the pulsing sections of a key over the pulsingelement of the shaft to which said pawl is fixed, the circuit throughone pair of the first named contacts being closed by operation of theswitch actuating member on one of the first named shafts in thedepression of a key in setting the mechanism to dialing operation, andmeans comprising a lock pin operatively engaging a recess in the firstside edge of said key for retaining the key normally in inoperativeposition.

4. In telephone dialers of they class described, a call actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an opposed tooth-like edge having pulsing sections,a pair of spaced shafts having longitudinal gear portions, said keysbeing spaced longitudinally of said gear portions with the gear racks ofsaid teeth in position to operatively engage said gear portions, anotherpair of shafts spaced from the first shafts and having longitudinallyextending pulsing elements adapted to operatively engage said pulsingsections, said first shafts being spring tensioned and having switchactuating members of insulating material on one end thereof, two pairsof contacts operated by said last named members and normally supportingthe contacts in open circuit position, the corresponding end of thesecond named shafts having insulated pulsing pawls mounted thereon, apair of pulsing contacts adjacent each pawl, one of the contacts of eachpair being actuated by the adjacent pawl in intermittently breakingcircuit through the last named contacts in pulsing a predetermined callnumber by movement of one of the pulsing sections of a key over thepulsing element of the shaft to which said pawl is fixed, the circuitthrough one pair of the first named contacts being closed by operationof the switch actuating member on one of the first named shafts in thedepression of a key in setting the mechanism to dialing operation, andthe second edge of each key having, beyond the pulsing section, recessesfacilitating swinging movement of the pulsing elements in positioningsaid elements for pulsing movement over the sections of the keys.

5. In telephone dialers of the class described, a call actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an opposed tooth-like edge having pulsing sections,a pair of spaced shafts having longitudinal gear portions, said keysbeing spaced longitudinally of said gear portions with the gear racks ofsaid teeth in position to operatively engage said gear portions, anotherpair of shafts spaced from the first shafts and having longitudinallyextending pulsing elements adapted to operatively engage said pulsingsections, said first shafts being spring tensioned and having switchactuating members of insulating material on one end thereof, two pairsof contacts operated by said last named members and normally supportingthe contacts open circuit position, the corresponding end of the secondnamed shafts having insulated pulsing pawls mounted thereon, a pair ofpulsing contacts adjacent each pawl, one of the contacts of each pairbeing actuated by the adjacent pawl in intermittently breaking circuitthrough the last named contacts in pulsing a predetermined call numberby movement of one of the pulsing sections of a key over the pulsingelement of the shaft to which said pawl is fixed, the circuit throughone pair of the first named contacts being closed by operation of theswitch actuating member on one ofthe first named shaftsin the depressionof a key in setting the mechanism to dialing operation, the second edgeof each key having, beyond the pulsing section, recesses facilitatingswinging movement of the pulsating elements in positioning said elementsfor pulsingmovement over the sections of the keys, at fingerpieceportion detachably coupled with the upper end of each key, and saidfingerpiece portion supporting an identifying strip characterizing theparticular telephone number called by the key. 1 i

6. In telephone dialers of the class described, a call actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an op posed tooth-like edge having pulsingsections, a pair of spaced shafts having longitudinal gear portions,said keys being spaced longitudinally of said gear portions with thegear racks of said teeth in position to operatively engage said gearportions, another pair of shafts spaced from the first shafts and havinglongitudinally extending pulsing elements adapted to operatively engagesaid pulsing sections, said first shafts being spring tensioned andhaving switch actuating members of insulating material one end thereof,two pairs of contacts operated by said last named members and normallysupporting the contacts in open circuit position, the corresponding endof the second named shafts having insulating pulsing pawls mountedthereon, a pair of pulsing contacts adjacent each pawl, one of thecontacts of each pair being actuated by the adjacent pawl inintermittently breaking circuit through the last named contacts inpulsing a predetermined call number by movement of one of the pulsingsections of a key over the pulsing element of the shaft to which saidpawl is fixed, all of the keys being formed from common key blanks, thepulsing section of each blank comprising a plurality of equally spacedteeth, and part of the teeth being removed in producing, on the section,a predetermined arrangement of spaced pulsing operations defining aspecific telephone call number.

7. In telephone dialers of the class described, a call actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an opposed tooth-like edge'having pulsing sections,a pair of spaced shafts having longitudinal gear portions, said keysbeing spaced longitudinally of said gear portions with the gear racks ofsaid teeth in position to operatively engage said gear portions, anotherpair of shafts spaced from the first shafts and having longitudinallyextending pulsing elements adapted to operatively engage said pulsingsections, said first shaft-s being spring tensioned and having switchactuating members of insulating material on one end thereof, two pairsof contacts operated by said last named members and normally supportingthe contacts in open circuit position, the corresponding end of thesecond named shafts having insulated pulsing pawls mounted thereon, apair of pulsing contacts adjacent each pawl, one of the contacts of eachpair being actuated by the adjacent pawl in intermittently breakingcircuit through the last named contacts in pulsing a predetermined callnumber by movement of one of the pulsing sections of a key over thepulsing element of the shaft to which said pawl is fixed, and said pawlshaving tensional means normally supporting said contacts in closedcircuit position.

8. In telephone dialers of the. class described, a call actuatingmechanism comprising a plurality of call keys,

each of said keys having a gear rack edge and an opposed tooth-like edgehaving pulsing sections, a pair of spaced shafts having longitudinalgear portions, said keys being spaced longitudinally of said gearportions with the gear racks of said teeth in position to operativelyengage said gear portions, another pair of shafts spaced from the firstshafts and having longitudinally extending pulsing elements adapted tooperatively engage said pulsing sections, said first shafts being springtensioned and having switch actuating members of insulating material onone end thereof, two pairs of contacts operated by said last namedmembers and normally supporting the contacts in open circuit position,the corresponding end of the second named shafts having insulatedpulsing pawls mounted thereorua pair of pulsing contacts adjacent eachpawl,

one of the contacts of each pair being actuated by the,

adjacent pawl in intermittently breaking circuit through the last namedcontacts in pulsing a predetermined call number by movement of one ofthe pulsing sections of a key over the pulsing element of the shaft towhich said pawl is fixed, said pawls having tensional means normallysupporting said contacts in closed circuit position, and that part ofthe second named shafts including said pulsing elements being ofirregular cross-sectional form and the shafts at opposed sides of saidelements being cutaway to provide free action of the elements withrespect to the pulsing sections of said keys.

9. In telephone dialers of the class described, acall actuatingmechanism comprising a plurality of call keys, each of said keys havinga gear rack edge and an opposed tooth-like edge having pulsing sections,a pair of spaced shafts having longitudinal gear portions, said keysbeing spaced longitudinally of said gear portions with the gear racks ofsaid teeth in position to operatively engage said gear portions, anotherpair of shafts spaced from the first shafts and having longitudinallyextending pulsing elements adapted to operatively engage said pulsingsections, said first shafts being spring tensioned and having switchactuating members of insulating material on one end thereof, two pairsof contacts operated by said last named members and normally supportingthe contacts in open circuit position, the corresponding end of thesecond named shafts having insulated pulsing pawls mounted thereon, apair of pulsing contacts adjacent each pawl, one of the contacts of eachpair being actuated by the adjacent pawl in intermittently breakingcircuit through the last named contacts in pulsing a predetermined callnumber by movement of one of the pulsing sections of a key over thepulsing element of the shaft to which said pawl is fixed, said pawlshaving tensional means normally supporting said contacts in closedcircuit position, the pulsing elements of said second named shafts comprising outwardly extending longitudinal flanges, and at least onesurface of each flange extending radially with respectto the axis of theshafts.

10. A call key for automatic telephone dialers of the class described,said key comprising an elongated member having opposed side edges, oneedge having a plurality of longitudinally and equally spacedcontinuously uninterrupted gear teeth to form a gear rack thereon, theother side edge having an elongated pulsing section defined by equallyspaced teeth, portions of the teeth being removed at intervals todefine, on said section, a plurality of call units, the number of teethin each unit defining the number of pulsing operations in transmittingthrough a telephone system a predetermined telephone number, and theupper end of the key having a detachable fingerpiece portion.

ll. A call key for automatic telephone dialers of the classdescribed,said key comprising an elongated memher having opposed side edges, oneedge having a plurality of longitudinally spaced gear teeth to form agear rack thereon, the other side edge having an elongated pulsingsection defined by equally spaced teeth, portions of the teeth beingremoved at intervals to define, on

said section, a plurality of call units, the number of teeth in eachunit defining the number of pulsing operations in transmitting through atelephone system a predetermined telephone number, the upper cnd of thekey having a detachable fingerpiece portion, and the second named edgeof the key above and below said pulsing section having elongatedrecesses.

12. A call key for automatic telephone dialers of the class described,said key comprising an elongated member having opposed side edges, oneedge having a plurality of longitudinally spaced gear teeth to form agear rack thereon, the other side edge having an elongated pulsingsection defined by equally spaced teeth, portions of the teeth beingremoved at intervals to define, on said section, a plurality of callunits, the number of teeth in each unit defining the number of pulsingoperations in transmitting through a telephone system a predeterminedtelephone number, the upper end of the key having a detachablefingerpiece portion, the second named edge of the key above and belowsaid pulsing section having elongated recesses, and the first named edgepor tion of the key, above the gear rack, having a substantially conicalrecess adapted to receive a lock pin in positioning the key in a dialer.

13. In automatic telephone dialers of the character described, whereintwo banks of keys are arranged in the dialer, each key having a gearrack edge and a pulsing section edge, a spring tensioned elongated gearshaft adjacent the gear rack edge of each key, another shaft, at thesecond named edge of each key, the last named shafts havinglongitudinally arranged and radially extending pulsing elements adaptedto operatively engage the pulsing section of said keys, means normallysupporting the keys in raised inoperative position with respect to saidshafts, two pairs of switch contacts arranged adjacent one end portionof the first named shafts, insulating means fixed to said ends of saidshafts operatively engaging said contacts to normally support thecontacts in open circuit position, two other pairs of contacts arrangedadjacent the corresponding ends of the second named shafts and normallyin closed circuit position, pawls on said ends of the second namedshafts operative ly engaging the last named switches to intermittentlybreak the circuit through said switches in passage of the pulsingelement of said shafts over the pulsing sections of said keys, andtensional means controlling operation of said pawls, whereby, in theactuation of a key to call a predetermined telephone number, one of thefirst named shafts is rotated to close the circuit through one pair ofthe first named switch contacts and actuate the adjacent element toposition the same for transmitting call pulsing operations in reversemovement of the key by engagement of the gear with the rack of said key.

14. In automatic telephone dialers of the character de scribed, whereintwo banks of keys are arranged in the dialer, each key having a gearrack edge and a pulsing section edge, a spring tensioned elongated gearshaft adjacent the gear rack edge of each key, another shaft, at thesecond named edge of each key, the last named shafts havinglongitudinally arranged and radially extending pulsing elements adaptedto operatively engage the pulsing section of said keys, means normallysupporting the keys in raised inoperative position with respect to saidshafts, two pairs of switch contacts arranged adjacent one end portionof the first named shafts, insulating means fixed to said ends of saidshafts operatively engaging said contacts to normally support thecontacts in open circuit position, two other pairs of contacts arrangedadjacent the corresponding ends of the second named shafts and normallyin closed circuit position, pawls on said ends of the second namedshafts operatively engaging the last named switches to intermittentlybreak the circuit through said switches in passage of the pulsingelement of said shafts over the pulsing sections of said keys, tensionalmeans controlling operation of said pawls, whereby, in the actuation ofa key to call a predetermined telephone number, one of the first namedagainst operation While the pulsing section of one key shafts is rotatedto close the circuit through one pair of is operatively engaging saidpulsing element.

the first named switch contacts and actuate the adjacent element toposition the same for transmitting call puls- RefefeIlCeS Clt 1n thefile Of thls patent ing operations in reverse movement of the key by en-5 UNITED S T PATENTS gagement of the gear with the rack of said key, andsaid 2,063,830 Rouse Aug. 8, 1933 pulsing element operatively engagingthe pulsing sections 2,398,019 MacKenzie Feb. 27, 1942 of adjacent keysof a bank locking said adjacent keys

